No, not the occupation.
To the extent the recent actions (or inaction) of the West can be blamed, you can blame it on getting rid of Saddam, or you can blame it on leaving Iraq too early, or you can blame it on policy in Syria. You can't blame it on sticking around in Iraq. Iraq was getting objectively better after the surge -- a (flawed) democracy was emerging, the economy was taking off, violent deaths were way down from their peak.
You can argue that Maliki forced the US out and let the country go to hell (in which case "deposing Saddam" is the Western sin), or argue that the US could have stayed if it wanted (in which case if you're a Democrat you can blame it on "deposing Saddam, because we couldn't stick around forever," and if you're a Republican you can blame it on Obama wanting to get out before the job was done to score political points.)
Other than that, though, you're left with earlier Western actions (Bush I, Sykes Picot...) or Assad or Maliki or every crazy Wahhabi cleric in the region of you want to give Arabs some credit and capacity for self-determination too.